The Development of Hierarchically Complex Equivalence Classes

Piaget postulated that one of the fundamental actions of people was to classify objects and actions. These classifications could be grouped together on the basis of the number of times these actions coordinate precursor actions. We call this number the order of hierarchical complexity when it refers to task demands and the stage when it refers to performance. Fourteen orders of such complexity have been analyzed. This paper introduces the notion that equivalence classes can be ordered according to their hierarchical complexity. Here, an adult task shows how the identity relations at each stage are used to define equivalence classes of the next stage. Results showed that some adults with postgraduate education detect metasystematic (12th order) equivalence classes.